Synthesis and characterization of aluminophosphate glasses with unique blue emission

Abstract

The aluminophosphate glasses were prepared by the melting-quenching technique and their optical and structural properties were investigated. The 56P2O5-20Al2O3 glass exhibits unique blue emission at 406 nm due to the phosphorus defect in the glass matrix. Addition of SiO2, ZnF2, or Li2O to 56P2O5-20Al2O3 glass matrix has different influence on formation of phosphorus defect resulting in different intensities of blue emission at 406 nm, though SiO2, ZnF2 or Li2O mostly enters the glass network as modifier. Structural analysis of P2O5-Al2O3 based aluminophosphate glasses by positron annihilation lifetime spectroscopy indicates that values of positron lifetimes and the corresponding intensities may be connected with the sizes and number of structural defects. Under excitation of 251 nm, a broad blue emission band and a red emission band were observed in the Mn-doped 56P2O5-20Al2O3-15SiO2-10ZnF2 glass, indicating the operation of energy transfer from the phosphorus defect to octahedrally coordinated Mn in the glass host.